Why do you want a full installer? Simply enroll to beta installs, and install it via software update. 10.13.1 and 10.13.2 running fine on MBP4,1. The bug with Safari/AppStore/any other app with WebView will be fixed with Onyx. Maybe something went wrong with some permissions.
First off, the updates via App Store seem to be only partial, after 17 minutes into the update (estimated: 47 mins.) the machine reboots, would it be a wild guess that this leaves me with a corrupted -only partially updated- system software?
Second off, I'd like to keep a bootable USB stick with the latest sytem at the ready.
Of course I'd prefer the Update method via App Store, it worked fine until 10.13.1. 10.13.2 betas 1-5 malfunction/misbehave as described above.
Your thoughts would be appreciated, @Czo